Navigation General · USCG Exam Prep
TVMDC Conversion Practice Questions
TVMDC Conversion is one of the Navigation Generaltopics tested on the USCG captain's license exam. Binnacle School has 10 questions on it — here are 5 to try right now, each with the correct answer and a written explanation of why.
1. Using the mnemonic 'True Virgins Make Dull Compass,' the order of correction from true to compass is:
- A.True → Variation → Magnetic → Deviation → Compass✓
- B.True → Deviation → Magnetic → Variation → Compass
- C.Compass → Deviation → Magnetic → Variation → True
- D.True → Magnetic → Variation → Deviation → Compass
Why: TVMDC: True → apply Variation → Magnetic → apply Deviation → Compass. Reading left to right, each step converts toward the compass reading. Reading right to left converts compass toward true.
2. Variation: 10° E, Deviation: 5° W. A true course of 090° converts to what compass course?
- A.075°
- B.085°✓
- C.095°
- D.105°
Why: Converting true to compass (uncorrecting): subtract East, add West. Magnetic = 090° − 10°E = 080°. Compass = 080° + 5°W = 085°. Answer: 085°C.
3. Variation: 7° W, Deviation: 3° E. A true course of 180° converts to what compass course?
- A.170°
- B.176°
- C.184°✓
- D.190°
Why: True→Compass (uncorrecting): subtract East, add West. Magnetic = 180° + 7°W = 187°. Compass = 187° − 3°E = 184°. Answer: 184°C.
4. Variation: 15° E, Deviation: 0°. A true course of 270° converts to what compass course?
- A.255°✓
- B.270°
- C.285°
- D.300°
Why: True→Compass (uncorrecting), deviation = 0: Magnetic = 270° − 15°E = 255°. Compass = 255° (no deviation). Answer: 255°C.
5. Variation: 5° E, Deviation: 8° E. A true bearing of 045° converts to what compass bearing?
- A.032°✓
- B.038°
- C.052°
- D.058°
Why: True→Compass (uncorrecting): subtract East, add West. Magnetic = 045° − 5°E = 040°. Compass = 040° − 8°E = 032°. Answer: 032°C.
Drill all 10 TVMDC Conversion questions
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